Can I Run my OEM Brake Pads on the Track?04.13.2020
by Jeff Ritter
I'm going to share a little secret with you: As delivered from the factory, the brakes on your car are not capable of handling repeated laps on a racetrack. They may not even be very good for autocross, drifting, or rally racing.I don't care if your calipers are painted red or gold, if you have gigantic carbon ceramic discs, or if your car is advertised as being optimized on the Nordschleife. Do you know why your brakes are not up to the task of a serious thrashing as delivered?It's the lowest common denominator rule.
Manufacturers try to make every car accessible to as many people as possible, including sportscars. That includes the guy who may have no idea how to even drive the car.Despite the hardcore enthusiast's wishes, that's why you don't see fixed-back race buckets in a stock Corvette (the big boys couldn’t shoehorn themselves in), or racing slicks on a Miata (people would hurt themselves in the rain). The same is true of your car's brake system.If a manufacturer delivered a 'track-day special' with an extremely noisy brake pad that ate discs, there would be countless complaints and warranty-related service calls. The Nissan GT-R is a perfect example.The owner's manual clearly states that the car has high performance brakes, and that they could make some noise. I was browsing one of the GT-R forums the other day, and sure enough there were numerous threads started by owners complaining about brake noise.
So, how do manufacturers address this problem? They compromise, and sometimes heavily. The fundamental dilemma of taking a road car on a racetrack is that it was designed to do so many other things besides going as fast as possible. A purpose-built racecar has no such identity crisis. The brakes fitted to your car as standard are one of the most glaring examples of this dilemma, and they're often the first vehicle system to wilt when leaned upon under heavy track use.
Most manufacturers err on the side of caution and choose stock brake pads as docile as possible for the street. They know that one day your girlfriend or wife will take your M3 to the store, and she'll tell you that there's something wrong with your "screechy brakes." Beginning in the year 2021, new laws will limit the amount of copper in brake pads, which will even further neuter the performance of stock brake pads.For day-to-day street driving, our goals and the vehicle manufacturers’ goals are very much in line. We'd all love our pads to have the following attributes:
- Never make any noise
- No dust on our fancy wheels
- Good cold bite on the way to work
- Effective in the rain and snow
- Last 100,000+ miles
- Never wear out our discs
When a track weekend rolls around however, our priorities shift dramatically. We want our pads to have the following traits:
- Enough heat capacity to never fade after repeated lapping on a racetrack
- Hard brake pedal/predictable torque response at all temperatures for precise brake pedal feel and modulation
- No required bed-in or preparation
- Immediate release from the discs when we release the brake pedal
- No uneven pad deposits or scoring of the discs
- Little to no wear as heat increases
See any differences between those two lists? The design objectives for street pads and track pads are completely at odds with each other and show virtually no similarities. As such, designing a brake pad to perform well on the street virtually ensures that it won’t work well on the racetrack, and vice versa.
What happens to stock brake pads on the track?
At track temperatures, OEM pads lose their ability to generate friction. Pad materials designed to offer low noise and low dust operation can’t handle repeated trips to 1200°F+. Every pad material has a maximum temperature at which it can generate mu. Once that temperature is surpassed, the pad no longer generates friction against the disc. This phenomenon is called pad fade. You stand on the brake pedal, the pedal feels firm, but the car doesn’t slow. If you’ve ever had this happen to you on the track, it’s a pucker factor 11 moment! With street pads, the drop-off in mu is typically rapid: The pad feels okay on one turn but loses a huge amount of grip in the next brake zone, many times leading to an off-track excursion. The mu of proper track pads tends to taper off much more gradually with temperature rise, so you have far more warning if your pads are going to give up on you.
After the pad has exceeded its maximum operating temperature and loses its ability to generate friction, it starts to melt and fall apart. What typically happens is that the pad comes off the backing plate in globs, and smears all over the disc face. These are typically referred to as uneven pad deposits on the disc face. The pad material creates high spots on the disc face, which causes a judder or vibration. Every time you apply the brakes and that high spot passes the point where the pads are squeezing the disc, you feel it as a thump through the brake pedal, and sometimes even the steering wheel. Sometimes those high spots can be removed, and other times they cannot. In other words, not only do you risk destroying your stock pads when running them on track, you also risk destroying your discs.
Even if the stock pad doesn’t melt and smear all over the disc face, at the very least it’s going to start burning very rapidly at track temps. We’ve seen people go through a set of OEM pads in a single 20-minute session on a tough braking track. Sometimes they run them down to the steel pad backing plates, which then gouge and destroy the softer iron discs. Even though OEM pads aren’t as expensive as proper track pads, the wear rates of stock pads turn them into a money pit when run on the track! If a good set of track pads costs you twice as much as a set of stock pads yet they last three times as long, those track pads are still providing a tremendous value vs. the OE pads. It’s not just a matter of one costing more than the other. When considering brake expenses at the track, you must always be thinking miles per dollar.
Finally, wasted track time is both costly and no fun!When you're sitting in the pits watching your buddy rip down the front straight, and your stock pads are a steaming pile of dust lying inside your wheels, you'll be wishing you took the hour on Friday night to change your pads. Not only will you be bummed, you’ll have wasted a considerable amount of money. Most track organizations charge $50 or more per track session ($50x5=$250/day). A couple missed track sessions due to fading brake pads add up to enough to pay for a set of proper track pads in the first place!
Below is a pad that was overheated and run all the way into the backing plate.
Below is a disc that was run on the track with OEM pads. The pads overheated and left pad deposits all over the disc face.
How are track and racing brake pads different?
Proper track or racing brake pads are made from considerably different materials than OEM road pads, which is why they perform so much better on the track. Their constituent ingredients are chosen to provide the pads with the following traits:
Far higher max operating temperature/fade resistance- Track pads can be run at far higher temperatures than road pads. The best ones can go to 1700-1800°F without any decline in friction level. That means you won’t have to worry about letting them cool down throughout the session (hurting lap times), nor will they simply give up on you without warning when heading into a turn (far safer).
No uneven pad deposits, judder, or vibration- As a result of their higher max operating temperature, the best racing pads won’t smear high spots of material onto your discs at the temperatures they may reach. Entering every turn with a thump-thump-thump through the brake pedal and steering wheel is extremely distracting, and could waste your hard-earned track time, your discs, and a sizeable stack of cash.
Predictable brake torque response- If you want to increase your driving skill and graduate to the next level, consistency will take you there. Brake pads that feel the same in every brake zone at all temperatures, like the Ferodo DS3.12, will go a long way towards improving your lap times and comfort on the track, as your mind will be free to focus on other things.
Long pad/disc life- Racing pads are designed to have far more durability than a road pad at elevated temperatures. Even though they cost more, the miles per dollar you get out of them are much higher on the track. They also save your discs from potentially ruinous uneven pad deposits, saving you even more money.
What else determines if my pads will survive the racetrack?
After nearly twenty years of helping many thousands of people with their brakes, I’ve determined that brakes are far down the list of modifications people make when they first get a new sportscar. Instead, they always go for more power, wheels, tires, suspension, etc. What you need to keep in mind is that every modification you make to your car and the nut behind the wheel will change the demands on your brake system, and you must adjust accordingly. Below are a few examples.
Tire choice is one of the greatest factors in determining how quickly your pads will fade on the track.Brakes don’t stop the car, but tires do. The stickier the tire, the more brake your car can use, and the more brake heat you will generate. More grip = more heat.If you're running street tires, or if it rains at an event, you won't be able to generate as much grip, and you won't tax your brakes as much. If you install Hoosiers on a dry track however, you’re going to significantly increase the amount of brake punishment.If your stock brake pads weren’t up to repeated lapping on stock tires, they certainly aren’t going to last with R compound tires.
If you add 50 horsepower to your car, you’re going to be hitting higher speeds at the end of straights, creating higher energy stops at every turn. You’ll be braking from a higher speed down to the speed required to enter the turn, which means transferring the energy from a disc that is spinning faster into heat. Again, greater demand on your brake system.
If your OEM brake pads weren’t up to the task of repeatedly stopping your car at the track when it was bone stock, how do you think your stock pads will perform now that the car is more capable in every performance metric?
Driver experience, braking technique, and stability control systems
One of the most seriously flawed, and most commonly posted, pieces of logic I see on the enthusiast forums goes something like this, “You’ve never driven anywhere but the street, so your first couple of trips to the track won’t tax your brake system too heavily. I’m sure your OEM brake pads will be just fine.”Wrong!
It's true that novice drivers might be easier on the brakes because their corner exit speeds are lower, and their resulting terminal speeds entering brake zones are therefore lower. However, what you frequently see is novice track drivers stabbing wildly at the brakes, staying on the brakes far too long, oscillating on and off brake in the same brake zone, and do all sorts of other things one would never expect from the passenger seat!
Novices also tend to (wisely) leave all vehicle electronic nannies engaged, such as stability/yaw control.When those systems are engaged, the car is constantly fighting oversteer, and most times it is doing so by engaging the inner rear brakes. The constant application of the brakes to prevent oversteer dishes out some serious brake punishment, and many times the intervention is so subtle that the novice driver doesn’t even know it’s happening.
All the above therefore makes it impossible to say that a novice driver will be fine on stock brake pads based on track experience alone. After your 25th event however, you'll likely be taxing your brakes very differently than you did during your first event. You'll be hitting higher speeds, entering and exiting corners faster and in a different way, and your car will likely have more grip and power than it did when you started because you’ve made numerous modifications to it. You may be much easier on your brakes at that point, because you’ve learned how to use them properly!
Look closely at the track you'll be driving to determine how demanding it will be on your pads. Tracks like Road America, Watkins Glen, and Sebring are devastating on brakes. Don’t even think about running your OEM pads on a track like these. Long straights followed by tight turns force you to repeatedly decelerate from a very high speed to a very low speed, creating high energy stops. The distance between stops will also impact the amount of heat retained in your brakes. If the track you’re driving has a steady succession of medium straights and tight turns, your brakes won't have much time to cool between stops. That means heat will continually build.Flowing tracks with long sweepers and no long straights are considerably easier on brakes (think Big Willow and Roebling Road).
OEM brake pads are designed to comfortably chase groceries, not lap times. If you want to play it safe and not risk damaging the major components of your brake system, don't EVER drive an OEM pad on a road course. You might think it will be more convenient and economical to run stock pads, but it will cost you time and money in the long run.
If you’d like to learn more about planning brake upgrades as your driving and car evolve, please be sure to visit the Essex Parts learning center and check out our video, “How to Plan for Future Brake Needs”.
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